[ThinLTO] Metadata linking for imported functions

[oota-llvm.git] / include / llvm / Transforms / Utils / ValueMapper.h

diff --git a/include/llvm/Transforms/Utils/ValueMapper.h b/include/llvm/Transforms/Utils/ValueMapper.h
index ed33413641810005095bb8e17048981060e737bd..7b1382854ba8d6510de69aaaa2c9d39f2c9f8fba 100644 (file)
--- a/include/llvm/Transforms/Utils/ValueMapper.h
+++ b/include/llvm/Transforms/Utils/ValueMapper.h
@@ -1,4 +1,4 @@
-//===- ValueMapper.h - Interface shared by lib/Transforms/Utils -*- C++ -*-===//
+//===- ValueMapper.h - Remapping for constants and metadata -----*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -12,18 +12,119 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef VALUEMAPPER_H
-#define VALUEMAPPER_H
+#ifndef LLVM_TRANSFORMS_UTILS_VALUEMAPPER_H
+#define LLVM_TRANSFORMS_UTILS_VALUEMAPPER_H
 
-#include "llvm/ADT/DenseMap.h"
+#include "llvm/IR/ValueMap.h"
 
 namespace llvm {
   class Value;
   class Instruction;
-  typedef DenseMap<const Value *, Value *> ValueMapTy;
+  typedef ValueMap<const Value *, WeakVH> ValueToValueMapTy;
+
+  /// ValueMapTypeRemapper - This is a class that can be implemented by clients
+  /// to remap types when cloning constants and instructions.
+  class ValueMapTypeRemapper {
+    virtual void anchor();  // Out of line method.
+  public:
+    virtual ~ValueMapTypeRemapper() {}
+
+    /// remapType - The client should implement this method if they want to
+    /// remap types while mapping values.
+    virtual Type *remapType(Type *SrcTy) = 0;
+  };
+
+  /// ValueMaterializer - This is a class that can be implemented by clients
+  /// to materialize Values on demand.
+  class ValueMaterializer {
+    virtual void anchor(); // Out of line method.
+
+  protected:
+    ~ValueMaterializer() = default;
+    ValueMaterializer() = default;
+    ValueMaterializer(const ValueMaterializer&) = default;
+    ValueMaterializer &operator=(const ValueMaterializer&) = default;
+
+  public:
+    /// The client should implement this method if they want to generate a
+    /// mapped Value on demand. For example, if linking lazily.
+    virtual Value *materializeDeclFor(Value *V) = 0;
+
+    /// If the data being mapped is recursive, the above function can map
+    /// just the declaration and this is called to compute the initializer.
+    /// It is called after the mapping is recorded, so it doesn't need to worry
+    /// about recursion.
+    virtual void materializeInitFor(GlobalValue *New, GlobalValue *Old);
+
+    /// If the client needs to handle temporary metadata it must implement
+    /// these methods.
+    virtual Metadata *mapTemporaryMetadata(Metadata *MD) { return nullptr; }
+    virtual void replaceTemporaryMetadata(const Metadata *OrigMD,
+                                          Metadata *NewMD) {}
+  };
+
+  /// RemapFlags - These are flags that the value mapping APIs allow.
+  enum RemapFlags {
+    RF_None = 0,
+
+    /// RF_NoModuleLevelChanges - If this flag is set, the remapper knows that
+    /// only local values within a function (such as an instruction or argument)
+    /// are mapped, not global values like functions and global metadata.
+    RF_NoModuleLevelChanges = 1,
+
+    /// RF_IgnoreMissingEntries - If this flag is set, the remapper ignores
+    /// entries that are not in the value map.  If it is unset, it aborts if an
+    /// operand is asked to be remapped which doesn't exist in the mapping.
+    RF_IgnoreMissingEntries = 2,
+
+    /// Instruct the remapper to move distinct metadata instead of duplicating
+    /// it when there are module-level changes.
+    RF_MoveDistinctMDs = 4,
+
+    /// Any global values not in value map are mapped to null instead of
+    /// mapping to self. Illegal if RF_IgnoreMissingEntries is also set.
+    RF_NullMapMissingGlobalValues = 8,
+
+    /// Set when there is still temporary metadata that must be handled,
+    /// such as when we are doing function importing and will materialize
+    /// and link metadata as a postpass.
+    RF_HaveUnmaterializedMetadata = 16,
+  };
+
+  static inline RemapFlags operator|(RemapFlags LHS, RemapFlags RHS) {
+    return RemapFlags(unsigned(LHS)|unsigned(RHS));
+  }
+
+  Value *MapValue(const Value *V, ValueToValueMapTy &VM,
+                  RemapFlags Flags = RF_None,
+                  ValueMapTypeRemapper *TypeMapper = nullptr,
+                  ValueMaterializer *Materializer = nullptr);
+
+  Metadata *MapMetadata(const Metadata *MD, ValueToValueMapTy &VM,
+                        RemapFlags Flags = RF_None,
+                        ValueMapTypeRemapper *TypeMapper = nullptr,
+                        ValueMaterializer *Materializer = nullptr);
+
+  /// MapMetadata - provide versions that preserve type safety for MDNodes.
+  MDNode *MapMetadata(const MDNode *MD, ValueToValueMapTy &VM,
+                      RemapFlags Flags = RF_None,
+                      ValueMapTypeRemapper *TypeMapper = nullptr,
+                      ValueMaterializer *Materializer = nullptr);
+
+  void RemapInstruction(Instruction *I, ValueToValueMapTy &VM,
+                        RemapFlags Flags = RF_None,
+                        ValueMapTypeRemapper *TypeMapper = nullptr,
+                        ValueMaterializer *Materializer = nullptr);
+
+  /// MapValue - provide versions that preserve type safety for Constants.
+  inline Constant *MapValue(const Constant *V, ValueToValueMapTy &VM,
+                            RemapFlags Flags = RF_None,
+                            ValueMapTypeRemapper *TypeMapper = nullptr,
+                            ValueMaterializer *Materializer = nullptr) {
+    return cast<Constant>(MapValue((const Value*)V, VM, Flags, TypeMapper,
+                                   Materializer));
+  }
 
-  Value *MapValue(const Value *V, ValueMapTy &VM);
-  void RemapInstruction(Instruction *I, ValueMapTy &VM);
 } // End llvm namespace
 
 #endif